1. Field of the Invention
The present invention relates to an image pickup apparatus and a phototaking lens used therein and, more particularly, to an image pickup apparatus such as a TV camera which is suitably used to attain focusing of the phototaking lens by selecting a control signal (operation signal) from a focus demand attached to the phototaking lens or a camera control unit (CCU) mounted on the camera body.
2. Related Background Art
The conventional methods of manual focusing (to be referred to as the xe2x80x9cfocus functionxe2x80x9d hereinafter) of a phototaking lens include the method of manually operating the focus ring (which is directly performed by the hand of a cameraman) and the method of electrically operating the focus mechanism of the phototaking lens by using an actuator such as a motor. When the focus mechanism of the phototaking lens is to be electrically operated in a TV camera or the like, focusing is directly performed from the phototaking lens side, or focusing is performed on the CCU (Camera Control Unit) mounted in a relay station electrically connected to the phototaking lens.
FIG. 8 is a block diagram for explaining focusing to be performed in a conventional TV camera.
Referring to FIG. 8, focusing of a phototaking lens 901 is performed from a demand 903 connected to the phototaking lens 901 or from a control knob 905 on a CCU 904 at the relay station 902 side. An R/L switch 906 on the CCU 904 is operated to choose between using the demand 903 of the phototaking lens 901 and using the control knob 905 of the CCU 904. xe2x80x9cRxe2x80x9d of the R/L switch 906 represents remote control, i.e., an operation from the control knob 905 of the CCU 904. xe2x80x9cLxe2x80x9d of the R/L switch 906 represents local control, i.e., an operation from the demand 903 connected to the phototaking lens 901.
In the image pickup apparatus having a conventional focus mechanism, the R/L switch on the CCU is operated to switch the focusing operation between the demand operation of the phototaking lens and the CCU. This arrangement poses the following problem.
Assume that a TV crew is shooting for a relay broadcast of a golf tournament, while the phototaking lens is set near the green of the 18th hole, and the CCU is mounted in a relay car near the club house. Normally, the cameraman who operates the phototaking lens performs focusing by operating the demand connected to the phototaking lens while watching the TV monitor. In this case, focusing is performed when the R/L switch of the CCU is set at xe2x80x9cLxe2x80x9d. In some cases, however, an operator performs fine focusing by using the CCU in the relay car while watching the monitor. In this case, focusing is performed after the R/L switch of the CCU is switched from xe2x80x9cLxe2x80x9d to xe2x80x9cRxe2x80x9d. If, however, the operator forgets to switch the R/L switch back from xe2x80x9cRxe2x80x9d to xe2x80x9cLxe2x80x9d after focusing with the CCU is complete, the cameraman cannot perform focusing at the phototaking lens side, which may pose a problem in shooting a TV program. In practice, the cameraman and the staff in the relay car exchange information through a network, such as an intercom, and hence serious trouble is unlikely to occur. This is, nevertheless, a drawback in terms of the utility of the photographing equipment system.
It is an object of the present invention to provide an image pickup apparatus suited for a TV camera, in particular, and a phototaking lens used therein, which can smoothly and reliably perform focusing and zooming of the phototaking lens by using a detection means for detecting the operation states of the demand (focus demand) of the phototaking lens and the control knob of a CCU and automatically switching focusing and zooming control on the basis of a signal from the detection means, without using an R/L switch in the CCU of the relay station, as has been used in the prior art.
According to the present invention, there is provided an image pickup apparatus for driving a moving lens in accordance with first and second command signals, comprising first detection means for detecting the first command signal, second detection means for detecting the second command signal, selection means for selecting one of the first and second command signals on the basis of output signals from the first and second detection means, and driving means for driving the moving lens on the basis of the command signal selected by the selection means.
The selection means includes a plurality of algorithms. The apparatus includes a setting means for selectively setting these algorithms. The selection means selects a command signal in accordance with the algorithm set by the setting means.
The above and other objects, features, and advantages of the present invention will be apparent from the following detailed description in conjunction with the accompanying drawings and the appended claims.